Method and apparatus for indicating control information in a wireless frame

ABSTRACT

A method, apparatus and system for transmitting control information in a header of a physical protocol data unit (PPDU), such as an IEEE 802.11 compliant PPDU. Embodiments include indicating control features in an EDMG PPDU for Wireless LAN communications. The method and system may include overloading at least one bit of a Scrambler Initialization Field in the PPDU header (e.g. the PHY header) to convey control information, as well as to be used to initialize the scrambler shift register. The same header bits are thus used for both purposes. Examples of control information include a primary channel, channel width or MIMO configuration to be used in further communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/730,679, filed on Apr. 27, 2022, which is a continuation of U.S.patent application Ser. No. 15/480,044, entitled “Method and Apparatusfor Indicating Control Information in a Wireless Frame” filed on Apr. 5,2017 and claims the benefit and priority from U.S. Provisional PatentApplication No. 62/334,749 filed on May 11, 2016 and to U.S. ProvisionalPatent Application No. 62/444,055 filed on Jan. 9, 2017, each of theabove being herein incorporated by reference.

FIELD

The present disclosure relates to an apparatus, system, and method forcommunicating between Wireless LAN wireless stations (STAs). Inparticular, the present disclosure relates to an apparatus, system, andmethod for indicating enhanced directional multi-Gigabit (EDMG) featuresin a Wireless LAN frame.

BACKGROUND

With the introduction of Wireless LAN radio/modems that allow for largerbandwidth communications, such as in EDMG communications, there areadditional communication channel features that allow for a range ofchannels to be established between STAs. Accompanying the additionalcommunication channel features is a need to exchange correspondingadditional control information in order to coordinate, among otheroptions, selection of a primary channel, static/dynamic channelbandwidth, multiple-input multiple-output (MIMO) configuration type,and/or transmit diversity setting in order to establish the channel forthe communication exchange.

One option for exchanging the additional control information is to addnew control bits to a header that corresponds to the additionalcommunication channel features. A problem with this option is that itmay require a longer Control header with an increase in complexity ofboth transmitter and receiver because the additional control bits mayrequire additional coding to error-protect those bits, and may causeproblems when interoperating with legacy STAs. Another option forexchanging additional control information is to append the informationin a Control trailer (See, for instance the IEEE document numbered IEEE802.11-16/0105r0, and entitled “Adding control trailer to control modePPDUs,” Jan. 17, 2016, by C. Cordeiro and A. Kasher, referred to hereinas IEEE 802.11-16/0105r0. A difficulty with using such a Controltrailers is that it can inefficiently add additional redundant bits tothe frame). A difficulty with using Control trailers is, as currentlycontemplated, they would inefficiently add additional redundant bits tothe frame. Accordingly, there is a need for a system and apparatus thatallows for efficiently exchanging the additional control information,while still presenting a backward compatible Control frame. In an aspectthere is a need for a backward compatible Control frame that conveysadditional control information without relying upon a Control trailer tocarry that information.

This background information is provided to reveal information believedby the applicant to be of possible relevance to the present invention.No admission is necessarily intended, nor should be construed, that anyof the preceding information constitutes prior art against the presentinvention.

SUMMARY

In accordance with embodiments of the present disclosure, there isprovided an apparatus, system, and method for communicating betweenWireless LAN wireless stations (STAs). In particular, embodiments of thepresent disclosure relates to an apparatus, system, and method for anEDMG STA to transmit Control frames and EDMG single carrier (SC) andEDMG orthogonal frequency division multiplexing (OFDM) frames thatinclude information to indicate related EDMG features using the legacyportions of a frame structure that is backward compatible for legacystations (STAs). In an aspect, the present disclosure relates to anapparatus, system, and method for an EDMG STA to transmit and exchangedata frames in a manner that includes additional signaling to supportthe EDMG features the legacy portions of a frame while remainingbackward compatibility to allow a legacy STA to decode the frames.

According to other embodiments of the present disclosure, there isprovided a transmitter for transmitting a physical layer protocol dataunit (PPDU) having a header, the header having a ScramblerInitialization Field. The transmitter includes at least a scramblerinitializer and a scrambler. The scrambler initializer is configured tooverload at least one bit of the Scrambler Initialization Field to carrycontrol information. The scrambler is configured to scramble content inthe header following the Scrambler Initialization Field and anassociated MAC frame or a portion of the MAC frame based on a scramblerinitialization value conveyed via the Scrambler Initialization Field. Inone aspect, the control information may indicate at least one of: aprimary channel to be used by the transmitter; a channel bandwidth to beused by the transmitter; and a MIMO type to be used by the transmitter.The scrambler initializer may overload all or fewer than all bits of theScrambler Initialization Field to carry the control information.

In accordance with embodiments of the present disclosure there isprovided a receiver for receiving a physical layer protocol data unit(PPDU) having a header, the header having a Scrambler InitializationField. The receiver includes at least a decoder and a descrambler. Thescrambling data extractor is configured to interpret at least one bit ofthe Scrambler Initialization Field as control information. Thedescrambler is configured to descramble the PPDU or a portion of thePPDU based on contents of the Scrambler Initialization Field. Thecontrol information may indicate at least one of: a primary channel tobe used by the transmitter; a channel bandwidth to be used by thetransmitter; and a MIMO type to be used by the transmitter.

In accordance with embodiments of the present disclosure there isprovided a method for transmitting a physical layer protocol data unit(PPDU) having a header, the header having a Scrambler InitializationField. The method includes, by a transmitting station having a scramblerinitializer and a scrambler: overloading, using the scramblerinitializer, at least one bit of the Scrambler Initialization Field tocarry control information. The method further includes scrambling, usingthe scrambler, the PPDU or a portion of the PPDU based on a scramblerinitialization value conveyed via the Scrambler Initialization Field.The control information may indicate at least one of: a primary channelto be used by the transmitter; a channel bandwidth to be used by thetransmitter; and a MIMO type to be used by the transmitter.

In accordance with embodiments of the present disclosure there isprovided a method for receiving a PPDU having a header, the headerhaving a Scrambler Initialization Field. The method includes, by areceiver having a scrambling data extractor and a descrambler:interpreting, using the scrambling data extractor, at least one bit ofthe Scrambler Initialization Field as control information; anddescrambling, using the descrambler, the PPDU or a portion of the PPDUbased on contents of the Scrambler Initialization Field. The controlinformation may indicate at least one of: a primary channel to be usedby the transmitter; a channel bandwidth to be used by the transmitter;and a MIMO type to be used by the transmitter.

BRIEF DESCRIPTION OF THE FIGURES

Further features and advantages of the present disclosure will becomeapparent from the following detailed description, taken in combinationwith the appended drawings, in which:

FIG. 1 illustrates a transmitting station and a receiving station,according to embodiments of the present disclosure.

FIGS. 2A to 2C illustrate methods for transmitting data according tovarious embodiments of the present disclosure.

FIGS. 3A to 3C illustrate methods for receiving data according tovarious embodiments of the present disclosure.

FIG. 4 illustrates a conventional 802.11ad frame format for wirelesscommunications.

FIGS. 5A, 5B, and 5C illustrate example header formats of Control, OFDMand single carrier modes, respectively, in 802.11ad.

FIG. 6 is a block diagram illustrating a scrambling process.

FIG. 7A illustrates prior art channelization used by EDMG STAs.

FIG. 7B illustrates prior art channelization used by EDMG STAs.

FIG. 8 illustrates a proposed 802.11ay PPDU.

FIG. 9 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using Control PHY withthe Primary Channel/Bandwidth.

FIG. 10 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using Control PHY withthe Static/Dynamic Bandwidth/Channel/Bandwidth.

FIG. 11 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using EDMG SC PHY andEDMG OFDM PHY with the Primary Channel/Bandwidth.

FIG. 12 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using EDMG SC/OFDM PHYwith the Static/Dynamic Bandwidth/Channel/Bandwidth.

FIG. 13 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using EDMG SC PHY andEDMG OFDM PHY with the MIMO.

FIG. 14 illustrates a table showing the relationship between theScrambler Initialization field when transmitted using EDMG SC PHY andEDMG OFDM PHY with the transmit diversity.

FIG. 15 illustrates a Channel Bandwidth Indication in Control PHYHeader.

FIG. 16 illustrates a Channel BW field definition in bit field B1 B2 B3in Control PHY Header.

FIG. 17 illustrates an embodiment of Channel Bandwidth indication inControl PHY Header.

FIG. 18 illustrates an embodiment of a definition for Channel BW fieldin bit field B1 B2 B3 in Control PHY Header.

FIG. 19 illustrates an additional embodiment of a definition for ChannelBW field in bit field B1 B2 B3 in Control PHY Header.

FIG. 20 illustrates a definition of bit allocation of Last RSSI fieldwhen transmitted using the EDMG SC or EDMG OFDM mode.

FIG. 21 illustrates a EDMG-Header-A field structure and definition for aSU PPDU.

FIG. 22 illustrates an embodiment of a definition of ScramblerInitialization field in DMG Header when transmitted using EDMG SC andEDMG OFDM mode.

FIG. 23 illustrates an apparatus according to embodiments of the presentdisclosure.

It will be noted that throughout the appended drawings, like featuresare identified by like reference numerals.

DETAILED DESCRIPTION

Various acronyms as used herein are defined in the followingnon-exhaustive list:

-   -   AP: Access Point    -   DMG: Directional Multi-Gigabit    -   EDMG: Enhanced Directional Multi-Gigabit    -   OFDM: Orthogonal Frequency Division Multiplexing    -   PBSS: Personal Basic Service Set    -   PCP: PBSS Coordinate Point    -   PHY: Physical Layer    -   PPDU: Physical Layer Protocol Data Unit    -   PSDU: Physical Layer Service Data Unit    -   SC: Single Carrier    -   STA: wireless station, including AP and Non-AP Stations

As will be readily understood, a signal such as used in IEEE 802.11conveys a sequence of bits which are set by a transmitting station andinterpreted by a receiving station. Setting a bit can refer toconfiguration, by a transmitting station, of a signal to be transmittedso that the bit will (more likely than not and subject to noise) beinterpreted by a receiving station as a particular binary value. A bitcan be set to either a ‘0’ or a ‘1’. Interpreting a bit by a receivingstation refers to processing the signal in an attempt to determine theintended value of the bit as set by the transmitting station. Encoding,modulating, demodulating and decoding of a signal in order to convey asequence of bits can be performed in a variety of ways as would bereadily understood by a worker skilled in the art.

As used herein, the term “overloading” refers to the configuration andusage of the same data (e.g. specified bits conveyed via a signal) forat least two different purposes. For example, a wireless signal which isinterpreted as an IEEE 802.11 frame can include a portion which isinterpreted and/or used in two different ways.

Embodiments of the present disclosure relate to overloading of portionsof an IEEE 802.11 frame, such as bits of the frame header, so that thevalues conveyed by these overloaded portions are concurrently used forinitialization of a scrambling operation as well as another purpose,such as to convey other control information. More particularly,embodiments of the present disclosure relate to overloading of bits ofthe Scrambler Initialization Field of a Physical Layer Protocol DataUnit (PPDU) carrying an IEEE 802.11 frame (e.g. an IEEE 802.11ay controlframe or data frame). The frame can refer to a MAC layer frame. In someembodiments, some of these bits are overloaded in a given PPDU, whileother ones of these bits are assigned values in a random orpseudo-random manner. As such, random or pseudo-random properties ofvalues carried in the Scrambler Initialization Field can be at leastpartially retained. In other embodiments, all of these bits areoverloaded in a given PPDU.

In some embodiments, the bits are overloaded to the same degree in allapplicable PPDUs. In other embodiments, the number of overloaded bitscan vary from PPDU to PPDU, for example on an as-needed basis oraccording to a schedule. It is noted that the Scrambler InitializationField can refer to a collection of contiguous or non-contiguous bits,conveyed via a PPDU, which are used both for scrambler initializationpurposes and another purpose. In particular, the ScramblerInitialization Field does not necessarily have to carry this particularname when referred to in a document describing operation of thetransmitter and receiver.

In particular, bits of data carried in some or all applicable PPDUs(e.g. in the Scrambler Initialization Field of the header thereof) areused to support scrambling and descrambling operations, while some orall of these same bits of data are also used to convey other controlinformation. This other control information can include, but is notnecessarily limited to: control information used to support EDMGfeatures (such as channel bonding features and MIMO features), a channelto be used for communication between wireless stations (such as aprimary channel), a bandwidth of the channel (or PPDU), an indication ofwhether static or dynamic bandwidth allocation should be employed, aparticular set of one or more channels to be used for communication(e.g. a channel allocation or set of channels making up achannelization), a type of MIMO to be used for communication, a transmitdiversity configuration to be used in communication, a number of spatialstreams being transmitted, or a combination thereof. For purposes ofthis disclosure, SISO is considered to be a special case of MIMO ortransmit diversity in which one transmitting antenna and one receivingantenna are employed.

As such, in various embodiments, some or all bits of the ScramblerInitialization Field are used (set by the transmitting STA andinterpreted by the receiving STA) to convey control information asspecified above, while also being used for scrambling and descramblingoperations for example as specified in existing, proposed versions ofthe IEEE 802.11 standard, as well as potentially being specified infuture versions of the standard, or as specified or used in comparablestandardized or non-standardized (existing or future) communicationprotocols.

Because the Scrambler Initialization Field is designed to operate withan arbitrary (e.g. random or pseudo-random) value, using this field toconvey data which is meaningful for another purpose (i.e. overloadingsome or all bits of the field in some or all applicable PPDUs) isexpected to have limited impact on communication operations and backwardcompatibility.

By overloading only part of the Scrambler Initialization Field, and/orby overloading the Scrambler Initialization Field in some but not allapplicable PPDUs, at least some desirable “random” properties of theScrambler Initialization Field can be retained, at least on average.Furthermore, if the overloaded data is sufficiently random orpseudo-random, at least some of the “random” properties of the ScramblerInitialization Field can be considered to be inherently retained, atleast by some measures. The potential desirability of random orpseudo-random values conveyed by the Scrambler Initialization Field willbe readily understood by a worker skilled in the art.

In some embodiments, overloaded bits conveyed via the ScramblerInitialization field can be made to exhibit pseudo-random properties bysetting and interpreting the overloaded bits in a manner which variespseudo-randomly, but which is commonly known to the transmitting andreceiving stations. For example, the transmitting and receiving stationscan access a commonly known sequence of bits which is considered to berandom or pseudo-random, at least for practical purposes. The sequenceof bits can be provided to the stations during an initializationoperation, generated based on a commonly observed phenomenon, orextracted from a predetermined part of the frame being transmitted or adifferent message exchanged between the two stations. As each overloadedbit is being set by the transmitting station, it can be XORed with a bittaken from the commonly known sequence of bits. Likewise, as eachoverloaded bit is being interpreted by the receiving station, it can beXORed with the same bit taken from the commonly known sequence. Bitsfrom the commonly known sequence can be used in order.

Because the bits of the Scrambler Initialization Field are used (viaoverloading) to convey other data (e.g. control information), the needfor additional fields in the header is mitigated and backwardcompatibility is maintained, without necessarily relying upon a Controltrailer to carry such other data.

Embodiments of the present disclosure can be applied to various frameswhich are used to communicate a scrambler initialization value. Examplesof such (e.g. MAC layer) frames include control frames (Request to Send(RTS), Clear to Send (CTS), Acknowledgement (ACK) frames, etc.) and dataframes.

According to an embodiment of the present disclosure, and with referenceto FIG. 1 , there is provided a transmitting wireless station 110, suchas an access point (AP) or non-access point (non-AP) wireless station.The transmitting wireless station 110 includes at least a scramblerinitializer 112 and a scrambler 114. The station 110 further includes awireless transmitter 115. The station 110 may also include an errorcorrection encoder 116, which can operate for example on the scrambleddata. The station can further include components such as but notnecessarily limited to a processor 120 and computer memory 122, orequivalent hardware.

The scrambler 114 is used to scramble the header information and thedata frame. The scrambler initializer 112 is configured to embed thecontrol information 140 into the Scrambler Initialization Field 134carried by a header 132. The control information 140 may be embeddedinto a portion 136 of the Scrambler Initialization Field 134, or thecontrol information 140 may be embedded into the entire ScramblerInitialization Field 134. The header 132 is part of a PHY protocol dataunit (PPDU) 130 to be prepared and wirelessly transmitted by the station110. The scrambler initializer 112 is also configured to deliver ascrambler initialization value (SIV) 142 into the ScramblerInitialization Field 134. As such, the Scrambler Initialization Field134 is overloaded to convey the scrambler initialization value 142 whichcarries the control information 140 as well. As such, the scramblerinitialization value 142 can contain the control information 140.

The scrambler 114 is configured to scramble the frame based on thescrambler initialization value 142. The scrambling is performed suchthat a receiver in receipt of the PPDU 130 can recover the scrambledframe by descrambling based on the scrambler initialization value 142,as conveyed via the Scrambler Initialization Field 134.

In various embodiments, scrambling and descrambling operations aresymmetric in the sense that they operate based on the same scramblerinitialization value in order to scramble and then descramble a headerand a frame portion. In such embodiments, the scrambler initializer 112and the scrambler 114 can share information so that the scrambler 114will perform scrambling based on the same scrambler initialization valueas is included into the header 132. For example, the scramblerinitializer 112 can determine the scrambler initialization value 142 andpass it to the scrambler 114. A receiving wireless station in receipt ofthe PPDU 130, and hence in receipt of the scrambler initialization value(as included into the header 132) can then descramble the frame portionbased on this value.

According to another embodiment of the present disclosure, and also withreference to FIG. 1 , there is provided a receiving wireless station150, such as an AP or non-AP wireless station. The receiving wirelessstation 150 includes a scrambling data extractor 155, a descrambler 160,a wireless receiver 165, and potentially other components such as butnot necessarily limited to an error correction decoder 152, a processor170 and computer memory 172, or equivalent hardware.

The receiving station 150 receives (via the wireless receiver 165) thetransmitted PPDU 130. The scrambling data extractor 155 is configured tointerpret the portion 136 of the Scrambler Initialization Field 134 inthe received header 132 as the control information 140. The scramblingdata extractor 155 may operate on the received header data, for examplefollowing error correction decoding by error correction decoder 152. Asmentioned above, the portion 136 corresponds to at least one bit of aScrambler Initialization Field 134, and can correspond to part or all ofthe Scrambler Initialization Field 134. The scrambling data extractor155 is further configured to interpret the (entire) contents of theScrambler Initialization Field 134 as the scrambler initialization value142. The scrambling data extractor 155 can pass the scramblerinitialization value 142 to the descrambler 160. The descrambler 160 isconfigured to descramble a portion of the received PPDU 130 based onthis scrambler initialization value.

It should be noted that, due to interference, noise, etc., the contentsof the PPDU 130 as seen by the receiving station 150 can differ from thecontents of the PPDU as provided by the transmitting station 110. Insome embodiments, the control information conveyed through ScramblerInitialize Field is protected through error correction coding tomitigate the impact of interference and noise.

Components such as the scrambler initializer, the scrambler, thescrambling data extractor, the descrambler, as well as other componentssuch as error correction encoders and decoders, can include circuitrysuch as integrated circuits configured to receive data, process thedata, and provide the processed data in a predetermined manner, as wouldbe readily understood by a worker skilled in the art. The components canbe high-speed digital circuits such as application specific integratedcircuits (ASICs). In some embodiments, the components can be implementedby a processor executing computer program instructions. The transmitterand receiver include radiofrequency components as would be readilyunderstood by a person skilled in the art.

FIGS. 2A, 2B and 2C illustrate methods for frame/PPDU transmission,according to potentially overlapping embodiments of the presentdisclosure. FIG. 2A illustrates a method 200 for transmitting aframe/PPDU by a transmitting wireless station, according to anembodiment of the present disclosure. The method 200 includes receiving205 control information to be conveyed in the Scrambler InitializationField of a header of the PPDU. The method further includes generating210 a scrambler initialization value (SIV) which includes the controlinformation, and which may also include one or more random orpseudo-random bits. As such, one or more predetermined bit positions ofthe SIV are overloaded with bits which are indicative of controlinformation. Some or all of the bits of the SIV can be overloaded withcontrol information. The method further includes embedding 215 the SIVinto the Scrambler Initialization Field located in the PPDU header. Theembedding can be performed as part of the generation of the PPDU, i.e.providing a designated type of information to be transmitted by thePPDU. Generating and embedding of the SIV can be done by a scramblerinitializer. The method further includes scrambling 220, using ascrambler, a portion of a PPDU associated with the frame, based on theSIV. Embedding 215 and scrambling 220 do not necessarily occursequentially in the illustrated order. The frame (and PPDU) issubsequently transmitted 225 by the transmitting wireless station. Thetransmission can include various steps such as channel coding,modulation, etc.

FIG. 2B illustrates a method 230 for transmitting a PPDU by atransmitting wireless station, according to another embodiment of thepresent disclosure. The PPDU includes a header having a ScramblerInitialization Field. The method includes overloading 235, using ascrambler initializer, at least one bit of the Scrambler InitializationField to carry control information. The method further includesscrambling 240, using a scrambler, a PPDU or a portion of the PPDU basedon a scrambler initialization value to be conveyed by the ScramblerInitialization Field. In various embodiments, the control informationindicates at least one of: a primary channel to be used by thetransmitter; a channel width (i.e. bandwidth) to be used by thetransmitter; and a MIMO type to be used by the transmitter.

It should be noted here that scrambling based on contents of theScrambler Initialization Field does not necessarily require thescrambler to read the Scrambler Initialization Field in the headeritself during the scrambling operation (indeed, the PPDU may not havebeen fully constructed prior to scrambling). Rather, the scramblerinitialization value may be generated by the transmitting STA and madeavailable both to the scrambler and for inclusion in the PPDU header.That is, scrambling is performed based on a scrambler initializationvalue which is (also) contained, or will be contained, in the ScramblerInitialization Field to be transmitted to the receiving station.

FIG. 2C illustrates a method 260 for indicating control features in anEDMG PPDU for wireless local area network (LAN) communications,according to another embodiment of the present disclosure. The method isimplemented for example by a transmitting wireless station. The methodoptionally includes selecting 265 at least one transmission controlsetting for the wireless LAN communications. The transmission controlsetting can be, for example, control information such as: a primarychannel to be used by the transmitter; a channel width to be used by thetransmitter; and/or a MIMO type to be used for the wireless LANcommunications. The method includes embedding 270 at least one selectedor predetermined transmission control setting into at least one bit of aScrambler Initialization Field of a physical layer (PHY) header. Themethod further includes scrambling 275 the PHY header and accompanyingdata based on contents of the Scrambler Initialization Field, forexample by initialising a scrambler bit shift register using the atleast one bit of the Scrambler Initialization Field. The method furtherincludes error-control encoding and transmitting 280 the scrambled PHYheader and accompanying data toward an intended recipient device.

FIGS. 3A, 3B and 3C illustrate methods for frame/PPDU reception,according to potentially overlapping embodiments of the presentdisclosure. FIG. 3A illustrates a method 302 for receiving a PPDU by areceiving wireless station, according to an embodiment of the presentdisclosure. The method 302 includes, upon receipt 305 of a frame/PPDU,detecting 307 a scrambler initialization value (SIV) conveyed in aScrambler Initialization Field corresponding to the received PPDU. Themethod further includes interpreting 310 some or all bits of the SIV ascontrol information, according to a predetermined interpretation mappingcertain bits of the SIV to certain predetermined types of controlinformation, such as an indication of primary channel, channel bandwidthand/or MIMO type. The detecting 307 and the interpreting 310 can beperformed by a scrambling data extractor. The method further includesdescrambling 315, using a descrambler, a portion of the received PPDUbased on the SIV. The interpreting 310 and descrambling 315 are notnecessarily performed sequentially in the illustrated order.

FIG. 3B illustrates a method 330 for receiving a frame/PPDU by areceiving wireless station, according to another embodiment of thepresent disclosure. The frame includes a header having a ScramblerInitialization Field. The method includes detecting 335 at least one bitof the Scrambler Initialization Field, and interpreting the at least onebit as control information. The method further includes descrambling 340at least a portion of the PPDU based on contents of the ScramblerInitialization Field (i.e. based on the scrambler initialization valuecontained therein). In various embodiments, the control informationindicates at least one of: a primary channel to be used by thetransmitter; a channel width (bandwidth) to be used by the transmitter;and a MIMO type to be used by the transmitter.

FIG. 3C illustrates a method 360 for indicating control features in anEDMG frame for wireless LAN communications, according to anotherembodiment of the present disclosure. The method is implemented forexample by a receiving wireless station, such as an intended recipientof an EMDG frame. The method includes receiving 365 a scrambled andencoded (e.g. channel encoded) transmission. The method further includesdecoding 370 the scrambled and encoded transmission. The method furtherincludes retrieving 375 control information by reading at least one bitof a Scrambler Initialization Field of a PHY header included in thedecoded transmission. The retrieved control information may correspondto at least one control feature in an EDMG wireless LAN communication.The received control information may be a primary channel; a channelwidth; and/or a MIMO type. The method further includes descrambling 380the decoded transmission based on contents of the ScramblerInitialization Field, for example by initialising a descrambler bitshift register using at least one bit of the Scrambler InitializationField. The method further includes conducting 385 the wireless LANcommunications using the control information and the decoded,descrambled transmission.

The present disclosure relates to an apparatus, system, and method forcommunicating between wireless stations (STAs), including AP and Non-APStations. Referring to FIG. 4 , an example prior art frame format ispresented. The example prior art frame format is the format used in802.11ad, for example as described in Section 21 of the IEEE ComputerSociety document entitled “IEEE Standard for Informationtechnology-Telecommunication and information exchange between systems;Local and metropolitan area networks—Specific requirements, Part 11:Wireless LAN medium Access Control (MAC) and Physical Layer (PHY)Specifications, Amendment 3: Enhancements for Very High Throughput inthe 60 GHz Band,” IEEE Std. 802.11ad-2012, Dec. 28, 2012 (referred toherein as 802.11ad). In FIG. 4 , a PPDU 10 consists of five fields: aShort Training Field (STF) 12, a Channel Estimation (CE) Field 14, aHeader Field 16, a Data Field 18, and Automatic Gain Control (AGC) andReceive/Transmit Training (TRN-R/T) Fields 20. As will be appreciated,the frames and fields illustrated in the Figures of this disclosure havebeen formatted for clarity and are not to scale indicative of a size ofeach field. In some cases, the fields are sized based upon a length ofthe reference text, and accordingly are not representative of the numberof bits contained within each field. Note, in some literature the STF12, CE Field 14, and Header Field 16 may be pre-fixed with a capital “L”to indicate that these are “Legacy” defined fields (e.g. L-Header). Forsimplicity and clarity the applicant has not adopted this nomenclaturein this disclosure.

The STF 12 is used for synchronization and differentiation of theControl PHY and the non-Control PHY. The CE Field 14 is used for channelestimation. Optionally, the CE Field 14 may be used for differentiationof single carrier (SC) PHY and OFDM PHY. The Header Field 16 consists ofor comprises several fields that define the details of the PhysicalLayer Protocol Data Unit (PPDU) to be transmitted. The Data Field 18consists of or comprises the payload data of the Physical Layer ServiceData Unit (PSDU) that is to be scrambled, encoded, and modulated. TheAGC and TRN-R/T subfields 20 are used for beam refinement and beamtracking.

The actual makeup of the Header Field 16 varies depending upon thespecific transmission modality. For instance, three examples of HeaderFields 16 are those used for Control PHY, OFDM PHY, and SC PHY. HeaderFields for Control PHY, OFDM PHY, and SC PHY refer, respectively, to thefields which include information used during transmission in order forthe receiver to conduct correct reception of a Control PHY PPDU, OFDMPHY PPDU, and SC PHY PPDU. Referring to FIG. 5A, a Header Field 16 a forControl PHY is illustrated. Further related details can be found forexample in Section 21.4 of 802.11ad. As illustrated, the Control PHYHeader Field 16 a includes a 1 bit Reserved Field 32, a 4 bit ScramblerInitialization Field 34, a 10 bit Length Field 36, a 1 bit Packet TypeField 38, a 5 bit Training Length Field 40, a 1 bit Turnaround Field 42,a 2 bit Reserved Field 44, and a 16 bit Header Check Sequence (HCS)Field 46.

Referring to FIG. 5B, a Header Field 16 b for OFDM PHY is illustrated.Further related details can be found for example in Section 21.5 of802.11ad. As illustrated, the OFDM PHY Header Field 16 b includes a 7bit Scrambler Initialization Field 50, a 5 bit Modulation and CodingScheme (MCS) Field 52, an 18 bit Length Field 54, a 1 bit AdditionalPPDU field 56, a 1 bit Packet Type Field 58, a 5 bit Training LengthField 60, a 1 bit Aggregation Field 62, a 1 bit Beam Tracking RequestField 64, a 1 bit Tone Pairing Type Field 66, a 1 bit Dynamic TonePairing (DTP) Indicator Field 68, a 4 bit Last Received Signal StrengthIndicator (RSSI) Field 70, a 1 bit Turnaround Field 72, a 2 bit ReservedField 74, and a 16 bit Header Check Sequence (HCS) Field 76.

Referring to FIG. 5C, a Header Field 16 c for Single Carrier PHY isillustrated. Further related details can be found for example in Section21.6 of 802.11ad. As illustrated, the Single Carrier PHY Header Field 16c includes a 7 bit Scrambler Initialization Field 80, a 5 bit Modulationand Coding Scheme (MCS) Field 82, an 18 bit Length Field 84, a 1 bitAdditional PPDU field 86, a 1 bit Packet Type Field 88, a 5 bit TrainingLength Field 90, a 1 bit Aggregation Field 92, a 1 bit Beam TrackingRequest Field 94, a 4 bit Last Received Signal Strength Indicator (RSSI)Field 100, a 1 bit Turnaround Field 102, a 4 bit Reserved Field 104, anda 16 bit Header Check Sequence (HCS) Field 106.

In preparation for transmission, the transmitting device performs ascrambling operation on all of the bits in the PPDU following theScrambler Initialization Field in the header except for those in AGC andTRN-R/T fields 20, using a scrambler initialization value obtained fromthe Scrambler Initialization Field. The scrambling operation reordersthe bits or updates the bit patterns of the header and data fields towhiten the data stream, that is to make it appear random from thetransmitter's perspective. Referring to FIG. 5A, all bits after bit B4would be scrambled based upon scrambler initialization bits, i.e. bitsx1, x2, x3, x4 of the scrambler shift register initialized using theScrambler Initialization Field 34 bits B1 to B4, i.e. bits B1 to B4 ofthe Header Field 16 a and bits x5, x6, x7 set to ‘1’. Referring to FIGS.5B and 5C, all bits after bit B6 would be scrambled based upon thevalues contained in the Scrambler Initialization Field 50, 80 bits B0 toB6, i.e. bits B0 to B6 of the Header Field 16 b or 16 c. Header Fieldbits are numbered for reference, beginning with “B0” and proceedingsequentially.

A common technique for whitening data by scrambling is to feed the datathrough a pseudorandom number generator that employs a seed value. Inthe case of 802.1 lad PHY (for example as described in Section 21 of802.11ad), for instance, the scrambler has been selected to use theoperation of XORing each bit in turn with a length 127 periodic sequencegenerated by the polynomial S(x)=x⁷+x⁴+1 for a given scramblerinitialization state. The PLCP header bits, with the exception of thefirst seven bits for the SC and OFDM cases illustrated in FIGS. 5B and5C and the first five bits for the control PHY case illustrated in FIG.5A, are placed one after the other. For the cases illustrated in FIGS.5B and 5C, bit B7 is placed first. For the case illustrated in FIG. 5A,bit B5 is placed first. The octets of the PSDU and the padding bits areplaced into a bit stream with bit 0 (the least significant bit (LSB)) ofeach octet being placed first and bit 7 of each octet (the mostsignificant bit (MSB)) being placed last.

For each PPDU, the transmitter selects a nonzero seed value for thescrambler (bits x₁ through x₄ for the Control PHY case illustrated inFIG. 5A; bits x₁ through x₇ for the SC PHY and OFDM PHY casesillustrated in FIGS. 5B and 5C). The 802.11ad standard proposes that theseed value is selected in a pseudo random fashion. The seed value isentered in the Scrambler Initialization Field 34, 50, and 80 of the PLCPheader 16 a, 16 b, and 16 c respectively. Each data bit in the DataField 18 of the PPDU is then XORed with the scrambler output (x₄ XOR x₇)and the scrambler content is shifted once.

The operation is diagrammatically illustrated in FIG. 6 , for anembodiment in which a shift register is used for implementation. Withinthe context of the Control PHY case (see FIG. 5A), the scramblingoperation is defined based upon the 4 bit Scrambler Initialization Field34. In this case the scrambler shift register 300 is initialized byinserting bit values from bits B1, B2, B3, and B4 of the 4 bit ScramblerInitialization Field 34 (and also of the PLCP header 16 a) into bits x₁,x₂, x₃, and x₄ of the scrambler shift register 300 illustrated in FIG. 6, and by setting bits x₅, x₆, and x₇ to ‘1’. The scrambling operationcan then proceed by inputting header bits starting from bit B5, andcontinuing for the remainder of the header 16 a and after the last bitB39 has been input, continuing by bits from the Data Field 18 until allbits have been processed, or another appropriate stopping condition hasbeen reached.

Within the context of the OFDM PHY and SC PHY cases (see FIGS. 5B and5C, respectively), the scrambling operation is defined based upon the 7bit Scrambler Initialization Field 50, 80. In this case the scramblershift register 300 is initialized by inserting bit values from bits B0,B1, B2, B3, B4, B5, and B6 of the 7 bit Scrambler Initialization Field50, 80 (and also of the PLCP header field 16 b or 16 c) into bits x₁,x₂, x₃, x₄, x₅, x₆, and x₇ of the scrambler shift register 300illustrated in FIG. 6 . The scrambling operation can then proceed byinputting header bits starting from bit B7, and continuing for theremainder of the header 16 a and after the last bit B63 has been input,continuing by bits from the Data Field 18 until all bits have beenprocessed, or another appropriate stopping condition has been reached.

The proposed IEEE 802.11ay standard (in its current form) includes thefeature that an EDMG STA is able to determine the primary channel andoccupied bandwidth of any EDMG PPDU that it receives. In order to enablebackward compatibility with legacy STAs, the Header of each EDMG PPDUcan be decoded by a legacy STA to detect the length and MCS in theHeader. Within this constraint, however, the EDMG STA frame may alsoneed to include the additional signaling required to support EDMGfeatures (e.g. channel bonding, & MIMO). This introduces limitations inthat there are not enough reserved bits in the Control header toaccommodate this additional signaling, and there are not enough reservedbits in Request to Send (RTS), DMG Clear to Send (CTS) for bandwidthsignaling.

As such, a technical problem with the prior art is recognized herein, inwhich it is difficult to efficiently include all necessary data into anapplicable IEEE 802.11ay-compatible frame while retainingbackward-compatibility of the data frame. The difficulty is due in partto the limited number of bits in the frame header relative to the numberof bits needed to convey all desired header information. Embodiments ofthe present disclosure are intended to address such a problem. Inparticular, as mentioned above, embodiments of the present disclosurerelate to use of certain bits (e.g. bits of the Scrambler InitializationField) of a transmitted message (e.g. an IEEE 802.11 frame) to conveydata that is used both for scrambling/descrambling operations as well asfor one or more other purposes.

Referring to FIGS. 7 a and 7 b , the prior art channelization used byEDMG STAs is illustrated (IEEE802.11/15-1358-09-00ay-specification-framework-for-tgay). The ability ofa particular device to use a channel also depends upon local regulatoryrules, and any additional rules prescribed by the 802.11 ay standard.The channelization illustrated in FIG. 7 b , will be referred to belowin the following examples.

Referring to FIG. 8 , the EDMG PLCP (Physical Layer ConvergenceProtocol) protocol data unit (PPDU) 400 currently proposed in 802.11ayis illustrated for reference. In the context of the EDMG PPDU 400, theL-Header 406 is the equivalent of the Header Field 16.

In the case of the 802.11ac [5, Sec 17.3.5.5], the scrambling operationis used within the context of the Data field. In the scramblingoperation in Data field, the Service field in DATA field is composed of16 bits including 7 Scrambler Initialization bits and 9 Reserved SERVICEbits all of which are set to ‘0’s. When the channel bandwidth in non-HTis not present, the scrambler initial state is set with pseudo randomnon-zero value. When the channel bandwidth in non-HT is present, thescrambler is initialized with Scrambling Sequence B0 through B6. If thechannel bandwidth in non-HT equals CBW20, bits B0 through B4 will be setto a nonzero pseudo random value, while bits B5, B6 indicate the channelbandwidth. Bits B0 through B3 will be set to 4-bit pseudorandom nonzerointeger if the channel bandwidth in non-HT equals CBW20 and the dynamicbandwidth in non-HT equals Static, and will be a 4-bit pseudorandominteger otherwise.

The currently proposed method for the IEEE 802.11ay standard includes afixed 18-byte information length Control Trailer Field included beforethe Data Field 18 (see, for instance IEEE 802.11-16/0105r0, “Addingcontrol trailer to control mode PPDUs”). A reserved bit in the HeaderField 16 may be allocated to indicate the presence of the ControlTrailer. Due to the overhead cost though, it is desirable to avoid useof the Control Trailer when control information is indicated by fewbits.

Embodiments of the present disclosure involve overloading at least onebit in the Scrambler Initialization Field 34, 50, 80 to carry controlinformation, instead of being set in pseudorandom fashion. In an aspect,the control information may identify the primary channel. In an aspect,the control information may identify the channel bandwidth. In anaspect, the control information may indicate a MIMO type. In an aspect,the control information may comprise a combination of two or more of theprimary channel identity, the channel bandwidth, and the MIMO type. Inan aspect, at least one bit in the Scrambler Initialization Field 34,50, 80 is overloaded to carry control information and at least one otherbit in the Scrambler Initialization Field 34, 50, 80 is set randomly, orpseudorandomly.

Several example embodiments of the present disclosure will now bedescribed. It should be appreciated that these example embodiments canbe varied or combined in a variety of ways. For example, the bits usedto convey control information, and the mapping between bit values andcontrol information (such as channel bandwidth and/or static/dynamicbandwidth modes), can be varied. Mappings between bit values and controlinformation are known apriori to both transmitting and receivingstations, so that control information can be signaled between the twostations.

Example 1— Control PHY; Primary Channel/Channel Bandwidth

As illustrated in FIG. 9 , an example Control PHY may be constructed toindicate each of the primary channel and the channel bandwidth byoverloading the Scrambler Initialization Field 34 in the Header Field 16a for a Control PHY PPDU. In Example 1, we assume there are five optionsfor the primary channel: i) the channel transmitting the PPDU; ii)channel #1; iii) channel #2; iv) channel #3; and, v) channel #4. We alsoassume that there are 4 available bandwidth options: a) 2.16 GHz; b)4.32 GHz; c) 6.48 GHz; and, d) 8.64 GHz.

Bits B1, B2, B3, and B4 of the Scrambler Initialization Field 34 (and ofthe Header Field 16 a) are overloaded to include the values listed inthe table illustrated in FIG. 9 that correspond to the primary channel,the channel bandwidth and the channel number corresponding to FIG. 7Aselected for that PPDU. That is, bits B1 to B4 of the ScramblerInitialization Field 34 are set to the value which corresponds,according to the table illustrated in FIG. 9 , to the desired channeland bandwidth selections. In the scrambling operation, bits B1, B2, B3,and B4 are entered into bits x₁, x₂, x₃, and x₄ of the scrambler shiftregister 300 in place of pseudorandom digits, and bits x₅, x₆, and x₇are each set to ‘1’ as was the previous case, i.e. as described withrespect to FIG. 6 . The right-most column in FIG. 9 indicates a channelnumber as defined in FIG. 7A.

Example 2—Control PHY: Static/Dynamic Bandwidth Operation in 802.11ay

As illustrated in FIG. 10 , an example Control PHY may be constructed toindicate each of the static/dynamic channel bandwidth setting and thechannel bandwidth by overloading the Scrambler Initialization Field 34in the Header Field 16 a for a Control PHY EDMG PPDU. In Example 2, bitB3 is used to indicate whether the channel bandwidth setting is staticor dynamic. Bits B1 and B2 are used to indicate the selected channelbandwidth, based on the assumption that there are 4 available bandwidthoptions: a) 2.16 GHz; b) 4.32 GHz; c) 6.48 GHz; and, d) 8.64 GHz.

In the case where the channel bandwidth setting is dynamic, the channelbandwidth can expand to include available channels. For instance, if two2.16 GHz channels are free, then one can transmit over 4.32 GHz; ifthree 2.16 GHz channels are free, then one can transmit over 6.48 GHz,and if four 2.16 GHz channels are free, one can transmit over 8.64 GHz.In the dynamic channel bandwidth setting, the bandwidth canautomatically vary between 2.16 GHz and a specified maximum channelbandwidth, inclusive. The bandwidth is restricted to multiples of 2.16GHz. The maximum channel bandwidth is set by bits B1 and B2, accordingto the rightmost two columns in FIG. 10 .

In the case where the channel bandwidth setting is static, then thebandwidth may be set to one of 4.32 GHz, 6.48 GHz, or 8.64 GHz. If asecondary 2.16 GHz channel within the wideband channel is not available,then the transmitter can restart the transmit procedure over the primarychannel. In the static channel bandwidth setting, the bandwidth is fixedat the specified value and does not vary with availability.

The channel bandwidth may be indicated by selecting one of the availablebandwidths (e.g. for this case 2.16 GHz, 4.32 GHz, 6.48 GHz, or 8.64GHz).

Bits B1, B2, and B3 of the Scrambler Initialization Field 34 areoverloaded to include the values listed in the table illustrated in FIG.10 that correspond to the static/dynamic channel bandwidth setting andthe channel bandwidth selected for that PPDU. In the scramblingoperation, bits B1, B2, and B3 are entered into bits x₁, x₂, and x₃ ofthe scrambler shift register 300 in place of pseudorandom digits, bit B4is selected pseudorandomly and entered into bit x₄ of the scramblershift register 300, and scrambler bits x₅, x₆, and x₇ are each set to‘1’ as was the previous case.

In other words, in Example 2, bits B1 and B2 of the ScramblerInitialization Field are set and/or interpreted according to the tableillustrated in FIG. 10 to convey that the channel bandwidth is amultiple of 2.16 GHz lying between 2.16 GHz and 8.64 GHz, inclusive.When the channel bandwidth as indicated by bits B1 and B2 is 4.32 GHz orgreater, bit B3 of the Scrambler Initialization field is set and/orinterpreted according to the table illustrated in FIG. 10 to convey thatthe channel bandwidth setting is static (when B3=‘0’) or dynamic (whenB3=‘1’). When the channel bandwidth as indicated by bits B1 and B2 is2.16 GHz, the issue of whether channel bandwidth is static or dynamic isnot relevant because both settings result in identical behavior. In thiscase, the value of bit B3 can be set to ‘1’ or ‘0’ arbitrarily, forexample randomly or pseudo-randomly. Such random or pseudo-randomsetting of B3 can improve the “whiteness” of scrambling, because B3 isalso part of the Scrambler Initialization Field.

Example 3—SC PHY and OFDM PHY: Primary Channel/Channel Bandwidth

As illustrated in FIG. 11 , an example SC PHY and OFDM PHY format may beconstructed to indicate each of the primary channel and the channelbandwidth by overloading the Scrambler Initialization Field 50, 80 inthe Header Field 16 b, 16 c for a SC PHY/OFDM PHY EDMG PPDU. In Example3, we assume there are four options for the primary channel: i) channel#1; ii) channel #2; iii) channel #3; and iv) channel #4. We also assumethat there are 4 available bandwidth options: a) 2.16 GHz; b) 4.32 GHz;c) 6.48 GHz; and, d) 8.64 GHz.

Bits B0, B1, B2, and B3 of the Scrambler Initialization Field 50, 80(and thus of the Header Field 16 b or 16 c) are overloaded to includethe values listed in the table illustrated in FIG. 11 , which correspondto the primary channel and channel bandwidth selected for that PPDU.That is, bits B0 to B3 of the Scrambler Initialization Field 50, 80 areset to the value which corresponds, according to the table illustratedin FIG. 11 , to the desired channel and bandwidth selections. In thescrambling operation, bits B0, B1, B2, and B3 are entered into bits x₁,x₂, x₃, and x₄ of the scrambler shift register 300 in place ofpseudorandom digits, and scrambler bits x₅, x₆, and x₇ may each be setpseudorandomly as was the previous case, i.e. as described with respectto FIG. 6 . The right-most column in FIG. 11 indicates a channel numberas defined in FIG. 7A.

Example 4 SC PHY and OFDM PHY: Static/Dynamic Bandwidth Operation in802.11ay

As illustrated in FIG. 12 , example SC PHY and OFDM PHY formats may beconstructed to indicate each of the static/dynamic channel bandwidthsetting and the channel bandwidth by overloading the ScramblerInitialization Field 50 in the Header Field 16 b for an OFDM PHY EDMGPPDU and the Scrambler Initialization Field 80 in the Header Field 16 cfor an SC PHY EDMG PPDU. In Example 4, bit B2 is used to indicatewhether the channel bandwidth setting is static or dynamic. Bits B0 andB1 are used to indicate the selected channel bandwidth, based on theassumption that there are 4 available bandwidth options: a) 2.16 GHz; b)4.32 GHz; c) 6.48 GHz; and, d) 8.64 GHz.

In the case where the channel bandwidth setting is dynamic, then thechannel bandwidth can expand to include available channels. Forinstance, if two 2.16 GHz channels are free, then one can transmit over4.32 GHz; if three 2.16 GHz channels are free, then one can transmitover 6.48 GHz, and if four 2.16 GHz channels are free, one can transmitover 8.64 GHz. In the dynamic channel bandwidth setting, the bandwidthcan automatically vary between 2.16 GHz and a specified maximum channelbandwidth, inclusive. The bandwidth is restricted to multiples of 2.16GHz. The maximum channel bandwidth is set by bits B0 and B1, accordingto the rightmost two columns in FIG. 12 .

In the case where the channel bandwidth setting is static, then thebandwidth may be set to one of 4.32 GHz, 6.48 GHz, or 8.64 GHz. If asecondary 2.16 GHz channel within the wideband channel is not available,then the transmitter can restart the transmit procedure over the primarychannel. In the static channel bandwidth setting, the bandwidth is fixedat the specified value and does not vary with availability.

The channel bandwidth may be indicated by selecting one of the availablebandwidths (e.g. for this case 2.16 GHz, 4.32 GHz, 6.48 GHz, or 8.64GHz).

Bits B0, B1, and B2 of the Scrambler Initialization Field 50 and 80 areoverloaded to include the values listed in the table illustrated in FIG.12 that correspond to the static/dynamic channel bandwidth setting andthe channel bandwidth selected for that PPDU. In the scramblingoperation, bits B0, B1, and B2 are entered into bits x₁, x₂, and x₃ ofthe scrambler shift register 300 in place of pseudorandom digits, bit B3through B6 are selected pseudorandomly and entered into bit x₄ throughx₇ of the scrambler shift register 300. Further, generally this examplecan limit the control features to be applied to Control frames, as wellas be applicable to EDMG SC and EDMG OFDM frames.

In other words, in Example 4, bits B1 and B0 of the ScramblerInitialization Field are set and/or interpreted according to the tableillustrated in FIG. 12 to convey that the channel bandwidth is amultiple of 2.16 GHz lying between 2.16 GHz and 8.64 GHz, inclusive.When the channel bandwidth as indicated by bits B1 and B0 is 4.32 GHz orgreater, bit B2 of the Scrambler Initialization field is set and/orinterpreted according to the table illustrated in FIG. 12 to convey thatthe channel bandwidth setting is static (when B2=‘O’) or dynamic (whenB2=‘1’). When the channel bandwidth as indicated by bits B1 and B0 is2.16 GHz, the issue of whether channel bandwidth is static or dynamic isnot relevant because both settings result in identical behavior. In thiscase, the value of bit B2 can be set to ‘1’ or ‘0’ arbitrarily, forexample randomly or pseudo-randomly. Such random or pseudo-randomsetting of B2 can improve the “whiteness” of scrambling, because B2 isalso part of the Scrambler Initialization Field.

Example 5—SC PHY and OFDM PHY: MIMO & Transmit Diversity

In addition or as an alternative to providing information about thechannel bandwidth and/or the channels used, the Scrambler InitializationField 50, 80 may be used to convey other control information. In thiscase, the other control information comprises a MIMO setting, or aTransmit Diversity setting. Because Examples 3, 4 utilized bits B0, B1,B2, (and also B3 in the case of Example 3) of the ScramblerInitialization Field 50, 80 for illustration purposes, Example 5 encodesthe other control information into bits B4 and B5 to illustrate anexample where the Primary Channel, Channel Bandwidth, and either MIMO orTransmit Diversity may be indicated within the Scrambler InitializationField 50, 80 at the same time. Thus, in some embodiments, Example 5 isimplemented concurrently with Example 3 or 4. It will be appreciatedthat the specific bits and bit order provided in these examples are forillustration purposes, and that other combinations and orders are alsocontemplated. Furthermore, control information such as a MIMO setting orTransmit Diversity setting can be indicated by bit overloading withoutnecessarily also indicating a Primary Channel and/or Channel Bandwidthsetting.

As illustrated in FIG. 13 , in the case of MIMO, for instance, bits B4and B5 (of the Scrambler Initialization Field 50 or 80, and thus also ofthe Header Field 16 b or 16 c) may be used to indicate the desired MIMOsetting, while bit B6 (which follows bit B5) may be selectedarbitrarily, for example pseudorandomly or to convey other controlinformation. A mapping between bits B4 and B5 and MIMO settings is shownin FIG. 13 . Bits B0, B1, B2, and B3 may either be selectedpseudorandomly, or may be used to convey other control information. Thebits of the overloaded Scrambler Initialization Field 50, 80 may then beused to initialise the scrambler shift register as described above.

As such, by setting the value of bits B4 and B5 appropriately, anindication can be conveyed of a MIMO setting (or lack thereof) to beused. Illustrated indications include an indication of Single InputSingle Output (SISO) operation, and indications of 2×2, 3×3 and 4×4 MIMOoperation. An N×N MIMO operation refers to operation in which N transmitantennas and N receive antennas are utilized, as would be readilyunderstood by a worker skilled in the art. SISO operation refers tooperation with 1 transmit antenna and 1 receive antenna.

FIG. 14 illustrates an alternative mapping between bits B4 and B5 of theScrambler Initialization Field 50 or 80 (and thus also of the HeaderField 16 b or 16 c) and corresponding MIMO transmit diversity settingcontrol information. By setting the value of bits B4 and B5appropriately, an indication can be conveyed of a type of transmitdiversity (or lack thereof) to be used. Illustrated indications includean indication of SISO operation, an indication of 2×1 transmit diversityoperation, and an indication of 4×1 transmit diversity operation. An N×1transmit diversity operation refers to operation in which N transmitantennas and 1 receive antenna are utilized, as would be readilyunderstood by a worker skilled in the art.

As illustrated in FIG. 14 , in the case of transmit diversity, forinstance, bits B4 and B5 may be used to indicate the transmit diversitysetting, while bit B6 may be selected arbitrarily, for examplepseudo-randomly or to convey other control information. Bits B0, B1, B2,and B3 may either be selected pseudo-randomly, or may be used to conveyother control information. The bits of the overloaded ScramblerInitialization Field 50, 80 may then be used to initialize the scramblershift register as described above. Further, generally this example canlimit the control features to be applied to Control frames, as well asbe applicable to EDMG SC and EDMG OFDM frames.

In some embodiments, whether a mapping between bits is interpreted asindicating a MIMO setting (e.g. as in FIG. 13 ) or a transmit diversitysetting (e.g. as in FIG. 14 ) can depend on an operating context knownto the transmitter and receiving stations. The operating context can beknown apriori or communicated between transmitter and receivingstations, for example using another overloaded bit of the ScramblerInitialization Field.

Example 6—Channel Bandwidth Indication in Control PHY Header

Referring to FIG. 15 , an example definition of channel bandwidthindication in a Control PHY Header is shown, in accordance with anembodiment of the present invention. In the illustrated definition, theScrambler Initialization Field is used with a control mode PPDU. Theexample Scrambler Initialization Field of FIG. 15 has reserved bits 22and 23 of the L-Header field being both set to ‘1’. FIG. 8 illustratesthe L-Header field 406. That is, the bits B22 and B23 of the Control PHYHeader field 16 a illustrated in FIG. 5A (and corresponding to theReserved field 44) are both set to ‘1’. In FIG. 15 and the followingdescription, bit numbers B1 to B4 refer to bits of the Control PHYHeader (e.g. for the bit numbering as illustrated in FIG. 5A). Thebracketed bit numbers (B0) to (B3) refer to an alternative numbering ofthe bits, for example a numbering of the bits of the ScramblerInitialization Field itself, starting at B0. In the scramblingoperation, when bits B1 and B2 are ‘0’ and Bits B3 and B4 are reserved,this indicates the presence of the control trailer. When bit B1 is ‘0’,B2 is ‘1’ and Bits B3 and B4 are reserved, this indicates the presenceof the EDMG-Header-A field, which implies that the PPDU is an EDMGcontrol mode PPDU. When bit B1 is ‘1’ and when the PPDU contains an RTSor DMG CTS frame, the Channel BW field indicates the bandwidth of thePPDU. Otherwise the Channel BW field is reserved. That is, setting bothbits B1 and B2 of the Control PHY Header field 16 a to ‘0’ is used toindicate the presence of a control trailer; and setting bit B1 to ‘0’and bit B2 to ‘1’ is used to indicate the presence of the EDMG-Header-Afield. In either case, bits B3 and B4 of the Control PHY Header field 16a are reserved. Further, setting bit B1 of the Control PHY Header field16 a to ‘1’, and further when the PPDU associated with the Control PHYHeader contains an RTS or (DMG) CTS frame, bits B2 to B4 of the ControlPHY Header field 16 a are used to indicate the bandwidth of the PPDU. Itis noted that, in some embodiments, the Scrambler Initialization Fieldfor the OFDM PHY Header as illustrated in FIG. 5B or the SC PHY Headeras illustrated in FIG. 5C can be defined similarly according to theprinciples illustrated in FIG. 15 .

In FIGS. 15 and 17 , reference [1] in the first row, rightmost columnrefers to a version of the IEEE document “P802.11ay™/D0.3; 10 DraftStandard for Information Technology; Telecommunications and InformationExchange Between Systems—Local and Metropolitan Area Networks—SpecificRequirements—Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) Specifications, Amendment 7: Enhanced throughputfor operation in license-exempt bands above 45 GHz,” IEEE ComputerSociety, March 2017.

Referring to FIG. 16 , an example definition for the Channel BW field in(i.e. indicated via) bit field B1, B2 and B3 as described above ispresented. In this definition, it is assumed there are four options forthe channels making up desired channelization: i) N; ii) N+1; iii) N+2;and, iv) N+3. As shown in FIG. 15 , N is the value of the lowest channelnumber over which the PPDU is transmitted. We also assume that there arefour available bandwidth options: a) 2.16 GHz; b) 4.32 GHz; c) 6.48 GHz;and, d) 8.64 GHz. The Channel BW field value is interrelated to theseoptions. For instance, if 2.16 GHz is the desired channel bandwidth, theChannel BW field value will be set to zero and all the channels from Nto N+3, will be available independent from the other channels. If 4.32GHz is the desired channel bandwidth, the Channel BW field value is setto ‘1’ if N is even and set to 2 if N is odd. Channels N and N+1, orChannels N+2 and N+3, can be used for channelization. The channel BWfield value in FIG. 16 is a numerical value between 0 and 5 which isencoded into the Channel BW field using a three-bit binaryrepresentation.

As illustrated in FIG. 17 , an embodiment of a definition of a channelbandwidth indication in a PHY Header (e.g. a Control PHY Header)according to the present disclosure is presented.

In FIG. 17 and the following description, bit numbers B1 to B4 refer tobits of the Control PHY Header (e.g. for the bit numbering asillustrated in FIG. 5A). The bracketed bit numbers (B0) to (B3) refer toan alternative numbering of the bits, for example a numbering of thebits of the Scrambler Initialization Field itself, starting at B0. Inthe scrambling operation, bits B1 and B2 being ‘0’ and bits B3 and B4being Pseudo Random indicate the presence of the control trailer. BitsB1 being ‘0’, B2 being ‘1’ and B3 and B4 being Pseudo Random indicatethe presence of the EDMG-Header-A field, which implies that the PPDU isan EDMG control mode PPDU. That is to say, setting B1 and B2 to ‘1’indicates the presence of the control trailer; and setting B1 to ‘0’ andB2 to ‘1’ indicates the presence of the EDMG-Header-Field. In eithercase, B3 and B4 can be set pseudorandomly. When bit B1 is ‘1’ and whenthe PPDU contains an RTS or DMG CTS frame, the Channel BW fieldindicates the bandwidth of the PPDU. Otherwise the Channel BW field isset pseudorandomly (or alternatively reserved). The Channel BW field isdefined as set in FIG. 18 or FIG. 16 , where N is the value of thelowest channel number over which the PPDU is transmitted. This approachto using the scrambler initiation field in the IEEE 802.11ay L-Header ofthe control mode is backward compatible with IEEE 802.1 lad. It is notedthat, in some embodiments, the Scrambler Initialization Field for theOFDM PHY Header as illustrated in FIG. 5B or the SC PHY Header asillustrated in FIG. 5C can be defined similarly according to theprinciples illustrated in FIG. 17 .

It is noted that, in FIG. 17 , when bit B1 is ‘0’, bits B3 and B4 areassigned values in a pseudorandom manner. As such, at least the portionof the Scrambler Initialization value being conveyed by bits B3 and B4(of the Control PHY Header 16 a) is assigned a value pseudorandomly.This tends toward providing randomization or “whiteness” of thescrambling operation, which is an intended feature of scrambling.

Example 7—Channel BW Field

Referring to FIG. 18 , an example definition for the Channel BW field inbit field B1, B2 and B3 of the Scrambler Initialization Field of a PHYHeader field (e.g. a Control PHY Header field, or another type of PHYHeader field), according to an embodiment of the present disclosure ispresented. In this example definition, it is assumed that only Channel 1through Channel 4 exist (or are being considered) in EDMGchannelization. Definitions for such numbered channels in the context ofEDMG channelization would be readily understood by a worker skilled inthe art. The channel BW for these channels is 2.16 GHz, i.e. 2.16 GHzeach.

When the Channel BW field value is zero, the desired channel bandwidthis 2.16 GHz with Channels 1, 2, 3 or 4 being allocated, i.e. any one ofthese channels can be used for PPDU transmission. When the Channel BWfield value is one, the desired channel bandwidth is 4.32 GHz withChannels 1-2, Channels 2-3 or Channels 3-4 being allocated. As usedherein, a range of channels separate with a dash “-” indicates that thisrange of channels are bonded. When the Channel BW field value is two,the desired channel bandwidth is 6.48 GHz with Channels 1-3 or Channels2-4 being allocated. When the Channel BW field value is three, thedesired channel bandwidth is 8.64 GHz with Channels 1-4 being allocated.The Channel BW field value being equal to four indicates carrieraggregation of two channels having bandwidths of 2.16 GHz and 2.16 GHz,where the two channels are adjacent, i.e., Channel 1 & Channel 2,Channel 2 & Channel 3 or Channel 3 & Channel 4 are allocated. TheChannel BW field value being equal to five indicates carrier aggregationof two channels having bandwidths of 2.16 GHz and 2.16 GHz, where thetwo channels are separated by one channel, i.e., Channel 1 & Channel 3or Channel 2 & Channel 4 are allocated. The Channel BW field value beingequal to six indicates carrier aggregation of two channels havingbandwidths of 4.32 GHz and 4.32 GHz, where the two channels are adjacentchannels, i.e., Channels 1-2 & Channels 3-4 are allocated. When theChannel BW field value is 7, the desired channel bandwidth is reservedand there is no channel allocation. That is to say, the Channel BW fieldvalue of 7 is reserved and is not associated with a channel bandwidth orchannel allocation. The channel BW field value in FIG. 18 is a numericalvalue between 0 and 7 which is encoded into the Channel BW field using athree-bit binary representation expressed via bits B1, B2 and B3 of thePHY header field.

Example 8—Channel BW Field

Referring to FIG. 19 , an example definition for the Channel BW field inbit field B1, B2 and B3 of the Scrambler Initialization Field of a PHYHeader field (e.g. a Control PHY Header field or other type of PHYHeader field), according to an embodiment of the present disclosure ispresented. In this example definition, it is assumed that only Channel 1through Channel 6 exist (or are being considered) in EDMGchannelization. The channel BW for these channels is 2.16 GHz.

When the Channel BW field value is zero, the desired channel bandwidthis 2.16 GHz with Channels 1, 2, 3, 4, 5 or 6 being allocated. When theChannel BW field value is one, the desired channel bandwidth is 4.32 GHzwith, Channels 1-2, Channels 2-3, Channels 3-4, Channels 4-5 or Channels5-6 being allocated. When the Channel BW field value is two, the desiredchannel bandwidth is 6.48 GHz with, Channels 1-3, Channels 2-4, Channels3-5 or Channels 4-6 being allocated. When the Channel BW field value isthree, the desired channel bandwidth is 8.64 GHz with Channels 1-4,Channels 2-5 or Channels 3-6 being allocated. The Channel BW field valuebeing equal to four indicates carrier aggregation of two channels havingbandwidths of 2.16 GHz and 2.16 GHz, where the two channels areadjacent, i.e., Channel 1 & Channel 2, Channel 2 & Channel 3, Channel 3& Channel 4, Channel 4 & Channel 5 or Channel 5 & Channel 6 areallocated. The Channel BW field value being equal to five indicatescarrier aggregation of two channels having bandwidths of 2.16 GHz and2.16 GHz, where the two channels are separated by one channel, i.e.,Channel 1 & Channel 3, Channel 2 & Channel 4, Channel 3 & Channel 5, orChannel 4 & Channel 6 are allocated. The Channel BW field value beingequal to six indicates carrier aggregation of two bonded channels havingbandwidths of 4.32 GHz and 4.32 GHz, where the two channels areadjacent, i.e., Channels 1-2 & Channels 3-4 or Channels 2-3 & Channels4-5 or Channels 3-4 & Channels 5-6 are allocated. The Channel BW fieldvalue being seven indicates carrier aggregation of two bonded channelshaving bandwidths of 4.32 GHz and 4.32 GHz, where the two channels areseparated by one channel, i.e., Channels 1-2 & Channels 4-5 or Channels2-3 & Channels 5-6 are allocated. The channel BW field value in FIG. 18is a numerical value between 0 and 7 which is encoded into the ChannelBW field using a three-bit binary representation expressed via bits B1,B2 and B3 of the PHY header field.

Example 9—Indication of MIMO Configuration in L-Header of EDMG SC andEDMG OFDM Mode

Similar to bandwidth indication in L-Header as defined in IEEE 802.11aySpecification Framework Document (SFD), it is desirable thatmultiple-input multiple-output (MIMO) configuration also be indicated inthe L-Header of (i.e. for) EDMG SC or EDMG OFDM mode. This may bedesirable, for example, in order for the receiver to have enough time toprepare the RF circuitry for MIMO reception. Embodiments of the presentdisclosure thus provide MIMO configuration information, for exampleoverloaded into one or more bits of the Scrambler Initialization Fieldor other bits carrying a scrambler initialization value.

Referring to FIG. 20 , an example definition of bit allocation of LastRSSI field when transmitted using the EDMG SC or EDMG OFDM mode ispresented. In this definition, the “IsSISO” field only indicates thatthe PPDU is single stream or multi-stream PPDU without detailed MIMOconfigurations. The Last RSSI field is illustrated in FIGS. 5B and 5C asfields 70 and 100, respectively. It should be emphasized that the bitnumbers “B0” to “B3” in FIG. 20 refer to bit numbers of the Last RSSIfield itself, not bit numbers of the overall header. That is, “B0” inFIG. 20 may correspond to “B41” in FIG. 5B or “B39” in FIG. 5C.Reference [1] in FIG. 20 again refers to the IEEE document“P802.11ay™/D0.3; 10 Draft Standard for Information Technology;Telecommunications and Information Exchange Between Systems—Local andMetropolitan Area Networks—Specific Requirements—Part 11: Wireless LANMedium Access Control (MAC) and Physical Layer (PHY) Specifications,Amendment 7: Enhanced throughput for operation in license-exempt bandsabove 45 GHz,” IEEE Computer Society, March 2017.

Referring to FIG. 21 , an example prior art EDMG-Header-A fieldstructure and definition for a Single User (SU) PPDU is presented. Inthis illustration, the “Number of SS” field indicates, in EDMG-Header-A,the number of spatial streams transmitted in the PPDU, which may be latefor MIMO indication.

As illustrated in FIG. 22 an indication of MIMO configuration inL-Header of EDMG SC and EDMG OFDM mode is presented according to anembodiment of the present disclosure. In this embodiment, Bits B0, B1,B2, B3 and B4 are assigned values randomly or pseudo-randomly. Bits B5,B6 and B7 are indicative of the Number of spatial streams (SS). Thevalue of bits B5, B6 and B7 plus one indicates the number of SSstransmitted in the PPDU. Bits B0 to B7 refer to bits of the L-Header,which represents the Scrambler Initialization Field. The bits are usedto indicate the number of spatial streams used in the data portion ofthe corresponding PPDU. Thus, control information conveyed via theScrambler Initialization Field, or otherwise overloaded with bitsindicative of a scrambler initialization value, can include controlinformation indicative of a number of spatial streams being transmitted,e.g. in a PPDU. Further, generally this example can limit the controlfeatures to be applied to Control frames, as well as be applicable toEDMG SC and EDMG OFDM frames.

FIG. 23 is a block diagram of a computing system 2300 that may be usedfor implementing the devices and methods disclosed herein. Specificdevices may utilize all of the components shown or only a subset of thecomponents, and levels of integration may vary from device to device.Furthermore, a device may contain multiple instances of a component,such as multiple processing units, processors, memories, transmitters,receivers, etc. The computing system 2300 includes a processing unit2302. The processing unit 2302 typically includes a central processingunit (CPU) 2314, a bus 2320 and a memory 2308, and may optionally alsoinclude a mass storage device 2304, a video adapter 2310, and an I/Ointerface 2312 (shown in dashed lines).

The CPU 2314 may comprise any type of electronic data processor. Thememory 2308 may comprise any type of non-transitory system memory suchas static random access memory (SRAM), dynamic random access memory(DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or acombination thereof. In an embodiment, the memory 2308 may include ROMfor use at boot-up, and DRAM for program and data storage for use whileexecuting programs. The bus 2320 may be one or more of any type ofseveral bus architectures including a memory bus or memory controller, aperipheral bus, or a video bus.

The mass storage 2304 may comprise any type of non-transitory storagedevice configured to store data, programs, and other information and tomake the data, programs, and other information accessible via the bus2320. The mass storage 2304 may comprise, for example, one or more of asolid state drive, hard disk drive, a magnetic disk drive, or an opticaldisk drive.

The video adapter 2310 and the I/O interface 2312 provide optionalinterfaces to couple external input and output devices to the processingunit 102. Examples of input and output devices include a display 2318coupled to the video adapter 2310 and an I/O device 2316 such as atouch-screen coupled to the I/O interface 2312. Other devices may becoupled to the processing unit 2302, and additional or fewer interfacesmay be utilized. For example, a serial interface such as UniversalSerial Bus (USB) (not shown) may be used to provide an interface for anexternal device.

The processing unit 2302 may also include one or more network interfaces2306, which may comprise wired links, such as an Ethernet cable, and/orwireless links to access one or more networks 2322. The networkinterfaces 2306 allow the processing unit 2302 to communicate withremote entities via the networks 2322. For example, the networkinterfaces 2306 may provide wireless communication via one or moretransmitters/transmit antennas and one or more receivers/receiveantennas. In an embodiment, the processing unit 2302 is coupled to alocal-area network or a wide-area network for data processing andcommunications with remote devices, such as other processing units, theInternet, or remote storage facilities.

Through the descriptions of the preceding embodiments, the presentinvention may be implemented by using hardware only or by using softwarefor execution on a hardware platform. Based on such understandings, thetechnical solution of the present invention may be embodied in the formof a software product. The software product may be stored in anon-volatile or non-transitory storage medium, which can be a compactdisk read-only memory (CD-ROM), USB flash disk, ROM, persistent RAM, orother non-transitory storage medium. The software product includes anumber of instructions that enable a wireless connecting computingdevice to execute the methods provided in the embodiments of the presentinvention. The software product may include a number of instructionsthat enable a computer device to execute operations for configuring orprogramming a digital logic apparatus in accordance with embodiments ofthe present invention.

All publications, patents and patent applications mentioned in thisSpecification are indicative of the level of skill of those skilled inthe art to which this invention pertains and are herein incorporated byreference to the same extent as if each individual publication, patent,or patent applications was specifically and individually indicated to beincorporated by reference.

Although the present invention has been described with reference tospecific features and embodiments thereof, it is evident that variousmodifications and combinations can be made thereto without departingfrom the invention. The specification and drawings are, accordingly, tobe regarded simply as an illustration of the invention as defined by theappended claims, and are contemplated to cover any and allmodifications, variations, combinations or equivalents that fall withinthe scope of the present invention.

1.-32. (canceled)
 33. A non-transitory computer readable storage medium storing computer instructions, which when executed by at least one processor, causing a transmitting station comprising the at least one processor to: overload at least one bit of a scrambler initialization field to carry control information, wherein the control information indicates a channel bandwidth, wherein the scrambler initialization field is in a header of a physical layer protocol data unit (PPDU); scramble, based on a scrambler initialization value conveyed via the scrambler initialization field, content in the header following the scrambler initialization field together with an associated MAC frame or a portion of the MAC frame to produce a scrambled sequence, and transmit the PPDU comprising the scrambled sequence; wherein the control information carried in the scrambler initialization field comprises one of: a four-bit sequence “0000” indicating the channel bandwidth is 2.16 GHz; a four-bit sequence “0100” indicating the channel bandwidth is 4.32 GHz; a four-bit sequence “1010” indicating the channel bandwidth is 6.48 GHz; and a four-bit sequence “1110” indicating the channel bandwidth is 8.64 GHz.
 34. The non-transitory computer readable storage medium of claim 33, wherein the control information further indicates at least one of: control information used to support EDMG features; a set of one or more channels to be used by the transmitter; a transmit diversity configuration to be used in communication; a transmit diversity configuration to be used in communication; and a number of spatial streams being transmitted.
 35. The non-transitory computer readable storage medium of claim 33, wherein the PPDU is an IEEE 802.11ay Control PHY PPDU.
 36. The non-transitory computer readable storage medium of claim 33, wherein the instructions, which when executed by the at least one processor, further cause the transmitting station to: encoding the scrambled sequence, which is indicative of the content in the header together with the associated MAC frame or the portion of the MAC frame.
 37. A non-transitory computer readable storage medium storing computer instructions, which when executed by at least one processor, causing a receiving station comprising the at least one processor to: receive a physical layer protocol data unit (PPDU) including a scrambled sequence indicative of content in a header together with an associated MAC frame or portion of the associated MAC frame, the MAC frame being carried by the PPDU; interpret at least one bit of a scrambler initialization field in the header as control information, the control information indicating a channel bandwidth; and descramble the scrambled sequence which is indicative of the content in the header together with the associated MAC frame or portion of the associated MAC frame, based on contents of the scrambler initialization field; wherein the control information carried in the scrambler initialization field comprises one of: a four-bit sequence “0000” indicating the channel bandwidth is 2.16 GHz; a four-bit sequence “0100” indicating the channel bandwidth is 4.32 GHz; a four-bit sequence “1010” indicating the channel bandwidth is 6.48 GHz; and a four-bit sequence “1110” indicating the channel bandwidth is 8.64 GHz.
 38. The non-transitory computer readable storage medium of claim 37, wherein the control information further indicates at least one of: control information used to support EDMG features; a set of one or more channels to be used by the transmitter; a transmit diversity configuration to be used in communication; a transmit diversity configuration to be used in communication; and a number of spatial streams being transmitted.
 39. The non-transitory computer readable storage medium of claim 37, wherein the PPDU is an IEEE 802.11ay Control PHY PPDU.
 40. The non-transitory computer readable storage medium of claim 37, wherein the instructions, which when executed by the at least one processor, further cause the transmitting station to: decode the scrambled sequence which is indicative of the content in the header together with the associated MAC frame or the portion of the MAC frame. 